Pipe bending device

ABSTRACT

A device for the continuous prebending, particularly of hotrolled pipes which are adapted to be wound on a separate reel after the prebending includes a magazine or removable block mounting a plurality of rollers for the bending operation. The magazine includes guide bars or supporting flanges which interengage with receiving structures on a drive frame containing the motor drive and speed gearing. The motor drive includes telescopic shaft elements which may be oriented in alignment with the corresponding shaft elements of the rollers and coupled thereto after the magazine is fitted to the frame. The rollers comprise calibrated bending and calibrating rollers, the latter being mounted on the magazine frame in a manner permitting adjustment of at least one of them. The pipe to be bent is advantageously fed through a hopper, or guide, and between opposed calibrated bending rollers and thereafter between pure calibrating rollers. The last group of rollers, namely the calibrating rollers are mounted in the magazine frame so that they can be moved through a wide range.

United States Patent [72] inventors Gerhard Steck Rbelnhausen; Hans-Dieter Weiterrnann, Duisburg, both of, Germany [2]] Appl. No. 782,282 [22] Filed Dec. 9, 1968 [45] Patented July 27, 1971 [73] Assignee DemogAktiengesellschflt Duisburg, Germany [54] PIPE BENDING DEVICE 13 Claims, 4 Drawing Figs.

[52] U.S.C1 72/171, 72/173, 72/175 [51] lnt.Cl 821d 5/14, B21d 9/10 [50] Field ofSearch 72/166, 170, 172, 174,175, 173, 171

[56] References Cited UNITED STATES PATENTS 928,073 7/1909 Schenider 72/175 1,804,468 5/1931 Jensen 72/174 X 1,868,341 7/1932 Yates 72/175 2,059,578 1 H1936 Henning 72/169 X Primary ExaminerMilton S. Mehr' Anomey-McGlew and Toren ABSTRACT: A device for the continuous prebending, particularly of hot-rolled pipes which are adapted to be wound on a separate reel after the prebending includes a magazine or removable blo'ck mounting a plurality of rollers for the bending operation. The magazine includes guide bars or supporting flanges which interengage with receiving structures on a drive frame containing the motor drive and speed gearing. The motor drive includes telescopic shaft elements which may be oriented in alignment with the corresponding shaft elements of the rollers and coupled thereto after the magazine is fitted to the frame. The rollers comprise calibrated bending and calibrating rollers, the latter being mounted on the magazine frame in a manner permitting adjustment of at least one of them. The pipe to be bent is advantageously fed through a hopper, or guide, and between opposed calibrated bending rollers and thereafter between pure calibrating rollers. The last group of rollers, namely the calibrating rollers are mounted in the magazine frame so that they can be moved through a wide range.

PATENTEDJULZHHYIV I 3.595052 SHEU 1 BF 3 Inventor GEmmno STEM nnus'mersre HEHeRmn/A/ PIPE BENDlNG DEVICE SUMMARY OF THE INVENTION This invention relates, in general, to pipe bending devices and, in particular, to a new and useful device particularly for the continuous prebending of hot-rolled pipes which includes a mounting frame with a motor drive and gearing and driving shafts for a plurality of bending rollers, the bending rollers being mounted in a removable magazine which may be engaged into the frame and oriented for connection of the rollers to their driving shafts.

Pipes having an outside diameter of up to about 70 mm. and a wall thickness of up to about 6 mm. are usually cut to lengths of up to 8 meters and stacked. Processing difficulties are encountered when long coils of pipe must be produced. The prefabricated pipes rust be cut corresponding to their anticipated use and then welded together. Apart from the fact that such a method is rather expensive, it also involves dangers since the welds are frequently subjected to rupture and/or corrosion and therefore require after treatment such as an X-ray examination, for example.

With the presently known devices, it is only possible to prebend and wind cold steel pipes with a relatively small outside diameter of about mm. In order to avoid ruptures, deformations and undesired changes in the material structure such pipes can only beprebent and wound when they have a rather large radii. This requires correspondingly dimensioned bending and winding devices which are costly.

in accordance with the present invention, there is provided a device which may operate to prebend pipes of relatively large caliber while they are still hot and which can be wound after prebending. The pipes which can be handled theoretically of, indefinite length, the length being limited only by the size of the blooms and the capacity of the series-connected winding reel to which they are directed. Because the pipes have a temperature in the range of about from 600 to 800 C. during bending, structural changes may be avoided, at least to a great extent.

The invention provides a multiroller system having a common drive which is coupled with the supporting frame for the device. The material to be bent is fed over a hopper and between roller sets which comprise alternately calibrated bending and pure calibrating rollers. The last group of rollers can be adjusted to achieve the preselected pipe bending and winding radius. The rollers are advantageously mounted in a magazine frame and at least the last group thereof may be adjustably positioned to achieve a desired bending and winding radius.

According to a feature of the invention, the roller system comprising five rollers and an infeed hopper, or guide, are ar ranged together in a magazine frame. The magazine is received within a slideway defined on the drive frame and it may be oriented in a manner to permit quick connection of the individual shafts to the roller drives. For this purpose, the driving shafts advantageously include telescopic sections to facilitate their alignment and connection to the roller shafts. The use of removable magazine permits the rapid and simple exchange of the bending rollers, particularly when it is necessary to change within the rolling program, for optimum utiliza tion of the plant, from a smaller caliber diameter to a larger one or vice versa. The magazine is in the form of a block having suitable apertures or openings in the range of the pipe inlet and outlet for facilitating the infeed and guidance of the pipe passed between the bending rollers. The design is such that the bending and calibrating rollers are protected against external influences and do not require any reconditioning until after the expiration of melt regular service life. The openings of the magazine also are such that the accumulation of scale is prevented. The magazine advantageously carries parallel substantially L-shaped guide bars on each side which may be inserted into receiving recesses of supporting elements carried on the drive frame. The receiving elements on the drive frame are advantageously of U-shaped configuration designed to receive the projecting portion of an L-shaped configuration guide on the magazine. The receiving sections advantageously include a slightly inclined portion inclined in the direction of the drive feed and this provides an extremely advantageous inexpensive and trouble-free mounting for the change magazine. The supporting frame and magazine also include interengageable bolts, journals, etc., which may be secured after the magazine is positioned within the frame.

A further feature of the invention is the mounting for the roller set which is positioned to operate on the pipe last. This roller set includes a bending and a calibrating roller. The bending roller is mounted on a pivot arm or lever which may be shifted under the control of a hydraulic motor. The calibrating roller may be shifted for effecting a variation of the pipe bending and winding diameter by the addition of spaces or shims in the mounting means therefor. A further feature is the provision of a spacer for the calibrating roller which engages in a manner to limit the adjusting movement of the bending roller of this roller set. The construction is such that the bending roller may be automatically positioned by the hydraulic motor. in order to avoid undesired deformations and to insure optimum roundness of the pipe to be bent, the calibrating roller adjustment prevents an excessive stroke of the bending roller. The rollers are mounted so that they can be adjusted to facilitate the changes of the winding diameter of the pipes within a wide range in the order of about 00 mm.

in accordance with a further feature of the invention, the driving mechanism contained in the frame includes telescopic drive shafts which are, in turn, connected at their upper ends into a gear housing which accommodates the individual gears on each drive shaft and a driving pinion gear connected to the drive motor therefor. The construction permits the collapsing movement and the storage of the identically formed drive shafts and also permits the synchronous drive of all the bending and calibrating rollers.

The apparatus also includes a member which is connected to the frame and which is movable to move the frame with the magazine through a path at'which the magazine intercepts a pawl. The pawl bears on stops of the magazine to move it away from the frame during the continuation of the movement thereof. in this manner, the magazine may be automatically stripped from its drive frame.

Accordingly, it is an object of the invention to provide an improved bending machine which includes a drive frame and a magazine mounting bending rollers which is adapted to be connected into the drive frame into a position at which the rollers may be connected to suitable driving shafts.

A further object of the invention is to provide a device for the continuous prebending particularly of hot-rolled pipes which are to be wound subsequently on a winding drum or similar device comprising a multiroller system which is driven from a common drive carried on a supporting drive frame, the roller system including a hopper for the infeed of the pipe to be bent and at least two sets of rollers, one including calibrated bending rollers and the other pure calibrating rollers the latter group of rollers acting on the pipe to be bent last and being adjustably mounted.

A further object of the invention is to provide a bending device which includes a mounting frame for the driving motor and driving gears for a plurality of roller shafts, the roller shafts being telescopical to permit them to be retracted for receiving a roller magazine which may be adjustably inserted into the drive frame, the roller magazine providing a mounting for a plurality of bending rollers and calibrating rollers, preferably in a manner permitting the adjustment for varying the bending characteristics.

A further object of the invention is to provide a bending device which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a front elevational view of a bending device constructed in accordance with the invention;

FIG. 2 is a section taken on the line 2-2 of FIG. 1;

FIG. 3 is a section taken on the line 3-3 of FIG. I; and

FIG. 4 is a top plan view of the magazine employed with the machine indicated in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, in particular, the invention embodied therein comprises a bending device generally designated 1 which includes a driving motor 2 mounted over a gear box 3 ofa main frame or drive frame 4.

In accordance with the invention, the drive frame carries a removable magazine or roller supporting block 5 which is shown in the engaged position in the drive frame and located over a base 18.

Driving power is transmitted by the driving motor 2 through a pinion 2a arranged on the shaft, as indicated in FIG. 2. The pinion 2a drives gears 6, 6 which are provided for each of the roller drive shafts 7. The drive shafts 7 are of telescopic construction and they each carry an end coupling 7a for coupling the shaft to a shaft 50 provided for each roller.

In accordance with a further feature of the invention, the rollers are all carried in a block or magazine 5. The rollers include bending rollers 8, 8a, 8b and calibrating rollers 9 and 9a. In addition to the rollers 8, 8a, 8b, 9 and 9a there is a guide 10 for the infeed of the pipe which is carried on the magazine at a location to feed the pipe between rollers 84 and 9 and 8a and 8.

A pipe to be prebent is introduced into bending apparatus in the direction of the arrow 52 indicated in FIG. 3. The pipe passes through the guide 10 and between the rollers 8a and 8 and 9 and the calibrating rollers 9 and 9a, and exits in the direction of the arrow 54. The pipe which is bent in the apparatus to a preselected radius is then delivered to a reel (not shown) for winding.

A feature of the magazine construction is that it is provided with parallel L-shaped guide bars 5a and 5b which interengage into U-shaped supports or bars 4a and 4b of the supporting frame 4. During this process, the magazine is further centered by bolts or journals 5d and 52 (FIGS. 3 and 4) which are carried on the rear wall 5c. The journals 5d and 5e are received in recesses 4c and 4d of the supporting frame 4 and then coupled. The coupling is effected, for example, by means of keys I] and 11a.

The rollers 8, 8a and 9 are supported directly on the magazine housing 5 but the last two rollers 8b and 9a are arranged for adjustment to provide for variation of the bending of the pipe. The bending roller 8b is used for the screw down and is mounted for rotation on a lever 12. The lever is pivoted on a pivot 12a of the magazine housing 5 and it is coupled to a hydraulic cylinder through a piston rod member 56 which is slidable therein. Suitable control means (not shown) are provided for operating the cylinder 13 to advance and retract the piston rod 56 in order to accurately position the roller 8b as desired and in accordance with the bending requirements.

The calibrating roller 9a which is arranged opposite to the bending roller 8b and cooperates therewith is secured to a flange 14 (FIG. 3) which can be shifted in directions either toward or away from the roller Sb. The roller 9a is moved in accordance with the required bending radius of the pipe to be bent. If displacement of the roller 9a is required, washers or shims 15 are added or removed from between the flange I4 and the inner wall 5f of the magazine. The edge 14a of the flange 14 limits the stroke of the bending roller 8b in order to prevent contact of this roller with the roller 9a.

The construction permits adjustment of the roller positions to provide a variation of the pipe bending diameter and winding radius in the range of from about 00 mm. In order to insure the optimum utilization of the bending device, for example, in a change of a bending program which would require a different set of bending and calibrating rollers, it is absolutely necessary to be able to remove the magazine 5 as quickly as possible and to exchange it for another one. In order to facilitate this operation, it is necessary to disengage the connection between the magazine 5 and the supporting frame 4 quickly and simply. The shafts 50 of each of the rollers may be easily disconnected from the coupling 7a of each of the drive shafts 7 such as by the removal of a connecting bolt for example. The keys II and 110, as well as the connection between the roller bearing arm 12 and the hydraulic cylinder 13, may all be disconnected in order to facilitate removal of the magazine 5.

After the easy and uncomplicated operations to remove the connecting couplings, the pawls 16 which are carried on the base 18, as shown in FIGS. I and 2, are oriented to extend through an opening in the base 18 at a location to engage the frame when it is moved backwardly in a direction of the arrow 58 by a movable linkage arm 17 which is connected to a suitable power source for this purpose (not shown). The drive frame 1, together with the magazine 5, is moved in the direction of the arrow 58 along the base 18 until the stops 5a which are carried on the underside or bottom 5g of the magazine contact the pawl 16. The magazine 5 is then uncoupled from the supporting frame 4 by advancing the guide bars 5b along the recesses of the bars 4b of the frame 4 to cause removal of the magazine 5 from the frame. The lifting movement is aided by the fact that the supporting bars 4b have lower surfaces which extend upwardly in the direction of the movement of the magazine relative to the frame which facilitates the lifting of the magazine 5 out of the frame.

What I claim is:

l. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe and one of which is arranged opposite one of said outer bending rollers, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in relation to the opposite calibrating roller for effecting preselected bending of the article passed between said bending roller and said one of said calibrating rollers.

2. A bending device according to claim 1 wherein said means for adjustably positioning said outer one of said bending rollers includes a lever mountingsaid top bending roller so that it may be moved toward and away from said opposite calibrating roller.

3. A bending device according to claim 1 including a guide mounted on said block adjacent said bending rollers and forming an inlet into which the pipe to be bent is directed and which guides the pipe in relation to said rollers.

4. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and, being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least'one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, said plurality of rollers including at least five rollers rotatably mounted on said roller block, said roller block comprising a magazine detachably positioned on said drive stand.

5. A bending device, according to claim 1, wherein said magazine comprises a block-shaped housing having an inlet opening adjacent one end and an outlet opening spaced from said inlet opening.

6. A bending device particularly for prebending hot-rolled pipes whichare to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including a lever pivoted on said block and rotatably carrying one of said rollers, and hydraulic motor means con nected to said lever for shifting said lever to vary the position of said one roller.

7. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including means for adjustably mounting at least one of said bending rollers of said calibrated bending roller set comprising a shim engageable with said block and having a portion limiting the adjustment of the others of said bending rollers.

8. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including a drive motor mounted on said stand, a plurality of drive shafts driven by said drive motor and adapted to be coupled to a respective one of each of said rollers, said shafts being telescopic.

9. A bending device particularly be prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand having a gear case thereon with a plurality of drive gears thereon, a driving motor connected to said drive gears to rotate said gears, a drive shaft affixed to each of said drive gears and extending outwardly from said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine detachably connected to said drive stand, and a plurality of rollers carriedon said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby.

10. A bending device particularly for prebending hot-rolled pipes which are to besubsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers for bending articles such as pipes rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated roller bending set of rollers between which the article to be bent is fed, at least one subsequent set of calibrating rollers, and means for adjustably positioning at least one of said bending rollers of said bending roller set for effecting preselected bending of the article passed therebetween, said plurality of rollers including at least five rollers rotatablymounted on said roller block, said roller block comprising a magazine detachably positioned on said drive stand and said drive stand includes a pair of spaced supporting bars each having a recess therein, said magazine having a complementary magazine support bar with a projection adapted to extend into the recess of said stand support bar.

11. A bendingdevice particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers for bending articles such as pipes rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of rollers between which the article to be bent is fed, at least one subsequent set of calibrating rollers, means for adjustably positioning at least one of said bending rollers of said bending roller set for effecting preselected bending of the article passed therebetween, a supporting frame carrying said drive stand, an ejection pawl carried on said supporting stand, and means for shifting said drive stand with said roller block to a position to engage said roller block with said pawl and for thereafter further shifting said drive shaft stand with said roller block engaged with said pawl in order to effect ejection of said roller block from said drive stand.

12. A bending device particularly by prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand having a gear case thereon with a plurality of drive gears thereon, a driving motor connected to said drive gears to rotate said gears, a drive shaft affixed to each of said drive gears and extending outwardly from said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine detachably connected to said drive stand, a plurality of rollers carried on said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby, and slide means on said magazine engageable with said frame permitting transverse fixed to each of said drive gears and extending outwardly from i said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine detachably connected to said drive stand, and a plurality of rollers carried on said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby, a mounting base for said drive stand upon which said drive stand is mounted and slide means defined between said mounting base and said drive stand and said magazine to permit transverse movement of said magazine, and a pawl on said supporting base engageable with said magazine for preventing movement thereof relative to said drive stand to cause ejection thereof when said drive stand is moved relative to said base after said pawl is engaged with said magazine and means engageable with said drive stand to displace said drive stand on said base and to cause ejection of said magazine from said drive stand. 

1. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe and one of which is arranged opposite one of said outer bending rollers, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in relation to the opposite calibrating roller for effecting preselected bending of the article passed between said bending roller and said one of said calibrating rollers.
 2. A bending device according to claim 1 wherein said means for adjustably positioning said outer one of said bending rollers includes a lever mounting said top bending roller so that it may be moved toward and away from said opposite calibrating roller.
 3. A bending device according to claim 1 including a guide mounted on said block adjacent said bending rollers and forming an inlet into which the pipe to be bent is directed and which guides the pipe in relation to said rollers.
 4. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, said plurality of rollers including at least five rollers rotatably mounted on said roller block, said roller block comprising a magazine detachably positioned on said drive stand.
 5. A bending device, according to claim 1, wherein said magazine comprises a block-shaped housing having an inlet opening adjacent one end and an outlet opening spaced from said inlet opening.
 6. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on saId drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including a lever pivoted on said block and rotatably carrying one of said rollers, and hydraulic motor means connected to said lever for shifting said lever to vary the position of said one roller.
 7. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including means for adjustably mounting at least one of said bending rollers of said calibrated bending roller set comprising a shim engageable with said block and having a portion limiting the adjustment of the others of said bending rollers.
 8. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers having profiles corresponding to the profile of the pipe to be bent and being rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of at least three bending rollers arranged in a generally triangular pattern with an inner one over which the pipe is adapted to be bent and two outer ones engageable with the opposite side of the pipe to be bent, at least one calibrating roller set of at least two calibrating rollers arranged to contact respective opposite sides of the pipe, and means for adjustably positioning at least an outer one of said bending rollers of said bending roller set in a position for effecting preselected bending of the article passed between said bending roller and one of said calibrating rollers, including a drive motor mounted on said stand, a plurality of drive shafts driven by said drive motor and adapted to be coupled to a respective one of each of said rollers, said shafts being telescopic.
 9. A bending device particularly be prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand having a gear case thereon with a plurality of drive gears thereon, a driving motor connected to said drive gears to rotate said gears, a drive shaft affixed to each of said drive gears and extending outwardly from said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine Detachably connected to said drive stand, and a plurality of rollers carried on said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby.
 10. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers for bending articles such as pipes rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated roller bending set of rollers between which the article to be bent is fed, at least one subsequent set of calibrating rollers, and means for adjustably positioning at least one of said bending rollers of said bending roller set for effecting preselected bending of the article passed therebetween, said plurality of rollers including at least five rollers rotatably mounted on said roller block, said roller block comprising a magazine detachably positioned on said drive stand and said drive stand includes a pair of spaced supporting bars each having a recess therein, said magazine having a complementary magazine support bar with a projection adapted to extend into the recess of said stand support bar.
 11. A bending device particularly for prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand, a roller block mounted on said drive stand, a plurality of rollers for bending articles such as pipes rotatably supported on said roller block, drive means on said drive stand connected to said rollers to rotate said rollers, said rollers including at least one calibrated bending roller set of rollers between which the article to be bent is fed, at least one subsequent set of calibrating rollers, means for adjustably positioning at least one of said bending rollers of said bending roller set for effecting preselected bending of the article passed therebetween, a supporting frame carrying said drive stand, an ejection pawl carried on said supporting stand, and means for shifting said drive stand with said roller block to a position to engage said roller block with said pawl and for thereafter further shifting said drive shaft stand with said roller block engaged with said pawl in order to effect ejection of said roller block from said drive stand.
 12. A bending device particularly by prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand having a gear case thereon with a plurality of drive gears thereon, a driving motor connected to said drive gears to rotate said gears, a drive shaft affixed to each of said drive gears and extending outwardly from said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine detachably connected to said drive stand, a plurality of rollers carried on said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby, and slide means on said magazine engageable with said frame permitting transverse displacement of said magazine in respect to said stand in a direction normal to said drive shafts after said drive shafts are uncoupled from said rollers.
 13. A bending device particularly by prebending hot-rolled pipes which are to be subsequently wound on a device such as a reel, comprising a drive stand having a gear case thereon with a plurality of drive gears thereon, a driving motor connected to said drive gears to rotate said gears, a drive shaft affixed to each of said drive gears and extending outwardly from said gear box, said drive shafts being telescopic and having coupling means thereon adjacent the end opposite from said gear box, a magazine dEtachably connected to said drive stand, and a plurality of rollers carried on said magazine each having a roller shaft projecting outwardly therefrom in alignment with a respective drive shaft and adapted to be coupled to said drive shaft for rotation thereby, a mounting base for said drive stand upon which said drive stand is mounted and slide means defined between said mounting base and said drive stand and said magazine to permit transverse movement of said magazine, and a pawl on said supporting base engageable with said magazine for preventing movement thereof relative to said drive stand to cause ejection thereof when said drive stand is moved relative to said base after said pawl is engaged with said magazine and means engageable with said drive stand to displace said drive stand on said base and to cause ejection of said magazine from said drive stand. 